.app-padding {
  padding: $app-padding;
}

.app-flex {
  display: flex;

  .app-flex-content {
    flex: 1;
  }
}

.app-flex {
  display: flex;
}

.app-flex-item {
  flex: 1;
}

.app-row {
  flex-direction: row;
}
.app-column {
  flex-direction: column;
}

// 垂直居中
.app-center {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
}
